/*
 *
 * Copyright Eclub organization.
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at

 * http://www.apache.org/licenses/LICENSE-2.0

 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 */

package com.eclub.emotion.rootstone.serializer.scanning;

import java.io.InputStream;
import java.util.Deque;
import java.util.LinkedList;
import java.util.NoSuchElementException;

import com.eclub.emotion.rootstone.server.ResourceFinder;

/**
 * 
 * TODO Description
 *
 * @author   jun.yang, Wincor Nixdorf International GmbH
 */
public class ResourceFinderStack implements ResourceFinder{

	private final Deque<ResourceFinder> stack = new LinkedList<ResourceFinder> ();
    private ResourceFinder current = null;

    @Override
    public boolean hasNext() {
        if(current == null) {
            if(!stack.isEmpty()) {
                current = stack.pop();
            } else {
                return false;
            }
        }

        if(current.hasNext()) {
            return true;
        } else {
            if(!stack.isEmpty()) {
                current = stack.pop();
                return hasNext();
            } else {
                return false;
            }
        }
    }

    @Override
    public String next() {
        if(hasNext()) {
            return current.next();
        }

        throw new NoSuchElementException();
    }

    @Override
    public void remove() {
        current.remove();
    }

    @Override
    public InputStream open() {
        return current.open();
    }

    public void push(ResourceFinder iterator) {
        stack.push(iterator);
    }

    @Override
    public void reset() {
        throw new UnsupportedOperationException();
    }

}


